A few weeks ago we released version 2.2.0, and now version 2.2.1 of DOMjudge, our programming contest jury system. I'm actually very satisfied with the 2.2 branch because it implements some important wishes that users of the system had, especially moving nearly all state into the one central database instead of spread over db, files and hosts. It is getting more and more complete on the functionality side. Our next target, 3.0, will focus on a different part: installing the system and getting it running is not quite trivial. The system has grown organically, and the current setup procedure tries to install everything at once, from building the judging environment, setting up the web interface to generating the documentation. We aim to pull that apart so it gets easier and the administrator keeps better oversight. But that's all for the next contest season. Meanwhile, the 2.2.x branch will be maintained for bugfixes at least until ultimo 2008.

This is 'back to school' season aroun here. So on Saturday we went and set up two desks for our two kids. And with that I finally converted 'their' computer to a working multi-seat setup. At first, I had fiddled with two distinct (ATI Radeon) graphics cards. Somehow I never got x11 to recognise both cards properly. But two cards are not needed. As the machine is running a standard Kubuntu setup, I just followed this excellent three-part tutorial for Ubuntu multi-seat setup which describes the process using nothing but standard Ubuntu software. From setting up a 'big desktop' spanning two screens (which is easy enough using one card via the vga and dvi outputs), it is fairly straightforward to modify the gdm.conf setup to spawn two gdm greeter instances using the Xephyr nesting xserver. So far, all is well. We'll see what possible shortcomings we will find. The GL extensions are not supported, so some eye-candy will be unavailable.

I have been playing too many puzzle games lately. This trivia question just popped into my head:

What command will never appear in a .bash_history file?

Unfortunately, I seem to have disproven the answer I originally had. I wonder if there are others? My original answer was going to be “unset HISTFILE”, but I can make it show up in my .bash_history file:

unset HISTFILE
export HISTFILE=/home/kees/.bash_history

The fall semester is right around the corner and I have spent the last week obsessively tweaking my hacker course. I think I finally crafted a syllabus I can live with for the rest of the semester. I say “live with” because of what I excluded, which I simply did not want to (notably there is no material on DeCSS/DMCA, hacking the I-Phone, and I wanted to do more on encryption). But the good thing is I will be teaching this again in the future and will learn how to rotate in and out some of this material. Now I am off to enjoy a final free day before teaching responsibilities really begin.

The current method of patching into place a series of ./configure variables as $(DEB_HOST_GNU_TYPE).cache files is becoming a pain - it blocks native builds of Emdebian packages for a start. So, I've been experimenting with a different method of support.
Centralised cache value support
Initially, I've collated all the current cache values needed (i.e. beyond the ones already provided for specific architectures) into /etc/dpkg-cross/cross-config.cache and have a script in emdebian-tools called emcache that will manage the central values by comparing them to the real values used in each build tree.
So, cache values, what are they?

1. Cross-builds fail if ./configure tries to compile a test program and then try to execute it because it will have been compiled with the cross-compiler - instead, the cross-build passes the value that the test was trying to calculate so that ./configure does not need to try to execute any cross-compiled code.


2. The values are derived from native builds, written to a $(DEB_HOST_GNU_TYPE).cache file that is passed to ./configure via debian/rules.


3. The values turn out to be mostly (completely?) architecture-independent, so are eminently suitable for collation into a central cache file.


4. Quite package-specific. There is some overlap but most are customised for a specific package. This led to a development of the central cache file: package-maintained cache files to support extensibility.

Package maintained cache files
I'm now experimenting with cache files written (and maintained) by packages during normal builds and dropped into /etc/dpkg-cross/cross-config.d/ - which would later migrate into dpkg support. Ideas welcome!
The basic idea will be that IF cross-building, the build process would check for /etc/dpkg[-cross]/cross-config.d/$source_package and, if found, add that to the cache value list for that build.
Cache files are shell scripts so this it be manageable to bring some intelligence to the process.
Where does MIPS come in?
Well, all the builds, so far, have been ARM or armel (where the cache values are likely to be identical) and i386 (which doesn't need a cross-compiler at all and therefore does not need cache files). MIPS is the first chance to check the cache values and ensure that the above criteria really are true.
Now that we have a volunteer looking at MIPS, the current MIPS builds are a suitable test bed.
What does this have to do with Debian?
Once Lenny is released, I'll be looking to implement this support via the long term mass bug filing for cross-build support into the packages themselves. It is possible that the process can be entirely automated - as long as the script knows which values are relevant. A normal cache file, post-build, can be very, very long whereas most cache files for Emdebian are just a few lines long - the longest is about 20 lines.
The current process is outlined on the Emdebian website, including a list of packages that currently need cache files to cross-build.
Oh, and just a note - when I start this phase of the long term mass bug filing, I'll first do delayed NMUs for the existing bug reports - hence the delay until Lenny is released.
In order to speed things along, I have also been doing some RC bugs - downgrading some, fixing others etc. (I've finished 6 since coming back from DebConf, so far, IIRC.) All efforts to get Lenny released will help Emdebian too, so if you want to help Emdebian, then help Lenny get out of the door and let's get to work on Squeeze.

(Squeeze is a great name for a release with lots of fixes for embedded stuff, don't you think?)

Among other things, my webmaster cooperative is an agent for the Phone Co-op. Particularly with Free Software, cost-efficient ways of downloading data is a good companion service to have and the Phone Co-op has given a good ADSL and calls service to my own home and office for a few years now. When there are problems, they’ve worked pretty well to fix them. Just last week, I had a phone call to tell me when routing problems in LINX were fixed… which was a great help. I don’t remember an ISP doing that for me for years. I think the last one was my university’s dial-up service, 10 or more years ago. Another unusual thing for a UK ISP is the excellent public position on the Phorm ad-snooper that I mentioned previously: We strongly oppose these practices, especially the loss of privacy [...] Phorm is not operating on our users’ lines and we have required and received assurances from our suppliers that this will remain the case. Our Chief Executive Vivian Woodell gave an interview to the FT (accept the first two cookies, then block the rest, else you only get two paragraphs) which has a pretty good explanation of how the business side of the cooperative works. We’re recruiting for Line Rental (PSTN and ISDN) until the end of the year, including special offers like residential Unlimited Anytime Calls for 7.95 a month (normally 9.99) at the moment, as well as the great climate-neutral and ethical policies - if your landline contract renewal comes up, give it a look. The Phone Co-op was ten years old in June, but there are still big challenges: I’d love to see a cooperative pay-as-you-go mobile phone service and the mobile contract offers still look a bit expensive to me (no bundled data on phones, 25 per month for a 3G data card). I’d also love to see support for some daring innovative solutions like customers owning their own tails (tails are the last link to their house, where most of the UK has a choice of one provider: BT), using that as a way to upgrade small towns and villages to fibre-optic, or offer resident-owned wifi. Update: As if by magic, Ofcom has started a social web consultation about mobile phone services. Go comment.

Say Hi to Squeeze, the Debian version that will be released after Lenny (and of course when it's ready)!

After 11 years 1 month and 28 days it's time for me to farewall Catalyst IT. While this is something that I've been working towards for the last couple of years, my reasons for leaving don't reflect any large dissatisfaction with Catalyst, but rather my own disinterest in fulfillling a role which is deemed appropriate to an executive director of the company it has become. As well, it is Catalyst's current and continuing success which provides me with the opportunity to fade out, like the cheshire cat, without the need to have strong plans. I do believe that the use and understanding of free and open-source software in New Zealand has matured to a point where there is the potential for an independent to make a few dollars reviewing or planning for open source projects in corporate and government areas. I hope I'll find out. And a great big thank you to every one of you staff, clients, suppliers and friends who has made Catalyst such a fantastic place to be a part of. It really will be a hard act to follow. :-)

I finally found the time today to dig into oldsys-preseed and what I found wasn't pleasant. In fact, I may have solved the mystery why some people trying to install Debian on their NSLU2 cannot connect to the installer via SSH. oldsys-preseed is used on certain NAS devices to read the network configuration from the original firmware and these values are used to bring up SSH in debian-installer. If you used DHCP in the original firmware to obtain an IP address, debian-installer will do the same. If you have a static IP config, debian-installer will use it. In theory, it's all pretty simple, but users often run into troubles when a static IP config is used (as is the case on the NSLU2). While you only need an IP address, netmask and gateway to bring up SSH (and then you could configure the rest, such as DNS and hostname), debian-installer expects everything at the same time. I've seen many cases where users couldn't connect to the installer because they forgot to configure their DNS in the original firmware or some other values they didn't think were important. Anyway, right now oldsys-preseed will use a static configuration if the firmware is configured this way even if it's clear that netcfg won't like this configuration because of missing values. The IP address and DNS are always required, but the netmask and gateway can be figured out automatically. I wanted to add a sanity check that would choose DHCP in case the IP address or DNS were not specified. While working on this sanity check, I noticed two things: First, the "empty" value oldsys-preseed preseeds when there's no netmask or gateway is not accepted by netcfg and leads to an error message (which the user cannot see because SSH is not up yet). I'm pretty sure I tested this scenario when I wrote oldsys-preseed but it clearly doesn't work today and I don't see how it could ever have worked. This is pretty significant because having an empty gateway is a valid configuration (if hopefully not too common). Second, it seems that it's impossible to create a preseed file that tells netcfg that no gateway should be used. If you preseed an empty value, netcfg will simple use .1 as the gateway. I've fixed the first problem and proposed a patch to put in a special case to allow preseeding of no gateway. The sanity check that chooses DHCP when the network configuration is incomplete is also there now.

The 500000th bug day is coming. Some of you may remember the contest I launched last year for people to bet on the day bug #500000 would be reported. The bug rate in Debian is about 1000 bugs in 6 days from my survey. So, as we're now at about #497300, bug #500000 should happen in 14 days. It seems that Kartik Mistry is about to win the contest. Indeed, he will if the bug is reported between Sept. 11th and Sept. 17th which probability is very high. Folks, prepare to send cheers to India! Unless the bug rate increases a lot and Miguel "xerakko" Gea wins. Miguel, I watch you: no MBF for you! I definitely lost when Aug. 22nd came. I was betting on a small rate increase which indeed did not happen. You can start now computing the #600000 bug day. There *will* be a contest for it...unless I launch one for bug #1000000...:-)

Michael Janke is writing a series of posts about estimating availability of systems, here is a link to the introduction [1]. He covers lots of things that people often miss (such as cooling). If you aren’t about to implement a system for reliability then it’s an interesting read. If you are about to implement a system where reliability is required and you have control of the system (not paying someone else to run it and hope for the best) then it’s an essential read. It will probably also be good to give this URL to managers who make decisions about such things. Interesting summary of the connections between the Iraq war and the oil industry in the Reid Report [2]. The suggestion made by one of the sources she cites is that the intention of the war was to reduce the supply of Iraqi oil to increase prices. Sam Varghese has written an essay about this which summarises where the Iraqi oil goes [3]. It seems that half of Iraq’s oil goes to US military use, the other half is used domestically, and some oil is imported as well! So because of the US occupation the country with the second largest known oil reserves is importing petroleum products! If the US military was to cease operations world-wide then the oil price would drop significantly, this doesn’t just mean the occupation of Iraq and the various actions in South America, but also the bases in Germany and Japan. Interesting paper by Alexander Sotirov and Mark Dowd about Bypassing Browser Memory Protection in Windows [4]. This paper is good for people who are interested in computer security but don’t generally use Windows (such as me), if you want to learn about the latest things happening in Windows land then this is a good place to start. A well researched article by Rick Moen about the unintended effects of anti-gay-marriage laws [5]. Maybe some of the “conservatives” who advocate such laws should get themselves and their spouses tested. It would be amusing if someone like Rush Limbaugh turned out to be involved in a “gay marriage”. What Sysadmins should know about exposure to hazardous materials [6]. High-level overview of the issues, probably a good start for some google searches to get the details. Diamond John McCain is an interesting blog about the 73 year old (who was born in Panama) candidate in the US presidential election [7]. Update: Corrected my statement about Iraq’s oil reserves based on a comment by Sam.

• [1] http://lastinfirstout.blogspot.com/2008/07/estimating-availability-of-simple_04.html


• [2] http://blog.reidreport.com/2008/08/war-for-iraqi-oil.html


• [3] http://gnubies.com/comment/oil.html


• [4] http://taossa.com/archive/bh08sotirovdowd.pdf


• [5] http://linuxmafia.com/faq/Essays/marriage.html


• [6] http://blogs.techrepublic.com.com/networking/?p=637


• [7] http://diamondjohnmccain.blogspot.com/

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If all goes according to plan, Helen, Ilenia and I will be in Vienna, Austria sometime in the next week or two, to register our daughter as a US citizen. As always, we're interested in meeting anyone local for alcohol/food/coffee/whatever, within the limits of our time there. Send email with a mobile number if you're interested in meeting up at some point. I'm not exactly a frequent traveler, but Ilenia and I both really enjoy meeting people when we go places, so I signed up for this to see if it helps put me in contact with people, either in places I go, or people visiting Innsbruck: http://www.dopplr.com/traveller/davidnwelton

There’s one thing that the Apple Mail client gets right which I’ve never seen anything else try to do - the way it formats messages. Most mail clients seem to offer plain text and HTML as user selectable options and do exactly what they’re told regardless of the content of the message. If HTML is enabled they always send a mail with both text/plain and text/html renditions of the message. Normally the plain text version is a fixed, 80 column version. This is wasteful of bandwidth, especially since very few users actually use any formatting at all, and means that mail programs that don’t do HTML have to treat the mails as though the fixed layout the sending system chooses is important even when it results in poor layout (for example, on mobile devices with small screens). What Apple Mail does here is to only enable the more complex formatting options if they add information that can’t be represented in the less complex formats. By default mails are sent in text/plain with the format=flowed option to let the reader know it can safely reflow the text and no HTML alternative is generated. If something that can’t be represented using format=flowed is included in the message then a HTML alternative is generated - transparently and without user intervention. This is good partly because it’s nice to see format=flowed used, it’s a nice technical solution to the problem, but mostly because it’s great user interface design. Most Apple Mail users will never notice if it is or isn’t generating HTML e-mail, they’ll just see that it’s doing what they expect and won’t have to deal with an option that they probably don’t understand or have much of a view on. Other users won’t be troubled with HTML generated by Apple Mail users unless there is some content in the formatting. It’d be good to see more MUAs implementing similar behavior, at least optionally.

I just read an interesting post about latency and how it affects web sites [1]. The post has some good ideas but unfortunately mixed information on some esoteric technologies such as infiniband that are not generally applicable with material that is of wide use (such as ping times). The post starts by describing the latency requirements of Amazon and stock broking companies. It’s obvious that stock brokers have a great desire to reduce latency, it’s also not surprising that Google and Amazon analyse the statistics of their operations and make changes to increase their results by a few percent. But it seems to be a widely held belief that personal web sites are exempt from such requirements. The purpose of creating content on a web site is to have people read it, if you can get an increase in traffic of a few percent by having a faster site and if those readers refer others then it seems likely to have the potential to significantly improve the result. Note that an increase in readership through a better experience is likely to be exponential, and an exponential increase of a few percent a year will eventually add up (an increase of 4% a year will double the traffic in 18 years). I have been considering hosting my blog somewhere else for a while. My blog is currently doing about 3G of traffic a month which averages out to just over 1KB/s, peaks will of course be a lot greater than that and the 512Kb/s of the Internet connection would probably be a limit even if it wasn’t for the other sites onn the same link. The link in question is being used for serving about 8G of web data per month and there is some mail server use which also takes bandwidth. So performance is often unpleasantly slow. For a small site such as mine the most relevant issues seem to be based around available bandwidth, swap space use (or the lack therof), disk IO (for when things don’t fit in cache) and available CPU power exceeding the requirements. For hosting in Australia (as I do right now) bandwidth is a problem. Internet connectivity is not cheap in any way and bandwidth is always limited. Also the latency of connections from Australia to other parts of the world often is not as good as desired (especially if using cheap hosting as I currently do). According to Webalizer only 3.14% of the people who access my blog are from Australia, they will get better access to my site if hosted in Australia, and maybe the 0.15% of people who access my blog from New Zealand will also benefit from the locality of sites hosted in Australia. But the 37% of readers who are described as “US Commercial” (presumably .com) and the 6% described as “United States” (presumably .us) will benefit from US hosting, as will most of the 30% who are described as “Network” (.net I guess). For getting good network bandwidth it seems that the best option is to choose what seems to be the best ISP in the US that I can afford, where determining what is “best” is largely based on rumour. One of the comments on my post about virtual servers and swap space [2] suggested just not using swap and referenced the Amazon EC2 (Elastic Computing) cloud service and the Gandi.net hosting (which is in limited beta and not generally available). The Amazon EC2 clound service [3] has a minimum offering of 1.7G of RAM, 1EC2 Compute Unit (equivalent to a 1.0-1.2GHz 2007 Opteron or 2007 Xeon processor), 160G of “instance storage” (local disk for an instance) running 32bit software. Currently my server is using 12% of a Celeron 2.4GHz CPU on average (which includes a mail server with lots of anti-spam measures, Venus, and other things). Running just the web sites on 1EC2 Compute Unit should use significantly less than 25% of a 1.0GHz Opteron. I’m currently using 400M of RAM for my DomU (although the MySQL server is in a different DomU). 1.7G of RAM for my web sites is heaps even when including a MySQL server. Currently a MySQL dump of my blog is just under 10M of data, with 1.7G of RAM the database should stay entirely in RAM which will avoid the disk IO issues. I could probably use about 1/3 of that much RAM and still not swap. The cost of EC2 is $US0.10 per hour of uptime (for a small server), so that’s $US74.40 per month. The cost for data transfer is 17 cents a GIG for sending and 10 cents a gig for receiving (bulk discounts are available for multiple terabytes per month). I am not going to pay $74 per month to host my blog. But sharing that cost with other people might be a viable option. An EC2 instance provides up to 5 “Elastic IP addresses” (public addresses that can be mapped to instances) which are free when they are being used (there is a cost of one cent per hour for unused addresses - not a problem for me as I want 24*7 uptime). So it should be relatively easy to divide the costs of an EC2 instance among five people by accounting for data transfer per IP address. Hosting five web sites that use the same software (MySQL and Apache for example) should reduce memory use and allow more effective caching. A small server on EC2 costs about five times more than one of the cheap DomU systems that I have previously investigated [4] but provides ten times the RAM. While the RAM is impressive, I have to wonder about CPU scheduling and disk IO performance. I guess I can avoid disk IO on the critical paths by relying on caching and not doing synchronous writes to log files. That just leaves CPU scheduling as a potential area where it could fall down. Here is an interesting post describing how to use EC2 [5]. Another thing to consider is changing blog software. I currently use Wordpress which is more CPU intensive than some other options (due to being written in PHP), is slightly memory hungry (PHP and MySQL), and doesn’t have the best security history. It seems that an ideal blog design would use a language such as Java or PHP for comments and use static pages for the main article (with the comments in a frame or loaded by JavaScript). Then the main article would load quickly and comments (which probably aren’t read by most users) would get loaded later.

• [1] http://highscalability.com/latency-everywhere-and-it-costs-you-sales-how-crush-it


• [2] http://etbe.coker.com.au/2008/08/27/killing-servers-virtualisation-and-swap/


• [3] http://www.amazon.com/b/?node=201590011


• [4] http://etbe.coker.com.au/2008/05/28/xen-hosting/


• [5] http://www.protocolostomy.com/2008/08/27/more-adventures-in-amazon-ec2-and-ebs/

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The McCain campaign made a great tactical move by choosing Sarah Palin. She appeals to all the constituencies where McCain was weak: women, Christians, Libertarians, small state residents, energy policy wonks, corruption fighters, capitalists, gun enthusiasts, and Tina Fey fetishists. Downsides? She is inexperienced in national affairs but I really don't think the average voter will care. After all many of them were willing to overlook a similar level of inexperience in Obama. And there is one minor possible ethics situation which again will only excite the true believers. When it turns out to be overblown it may actually rebound in Palins favor as an example of MSM manipulation. She can also take the change meme away from the Democrats though that was already on the rocks what with the FISA vote and the choice of Neil Kinnock as his VP nominee. No, the lacklustre convention in Denver clearly showed that far from being the post-ideological, audaciously hopeful candidate of the future, Barack Obama is merely John Kerry with rhythm. So what do the Dems have have left? The traditional Democratic themes of "We're not Bush" (that worked sooo well the last two times didn't it?) and "The Earth is about to explode in a fiery cataclysm." As the situation in Iraq improves, the economy climbs upwards from recession and petrol prices continue to come down its going to be harder to sustain the necessary level of gloom and doom. While Republicans shouldn't exhale just yet (and the title of this post is just a teensy bit hyperbolic,) things are looking pretty good for us at the moment.

According to the Slashdot article and the StopSoftwarePatents.org website itself and on Digg, the anti-software-patent activists are attempting a world-wide event on the 24th of September as a world-wide day against software patents. USA has them via a weird court ruling, Japan has them as well (not sure why), there have been efforts to force software patents on EU, India, Australia and many other countries either by Microsoft lobbies or even via US trade treaty pressure. While lobbying by local Microsoft branches and their pet companies can be countered locally, like I and many others did in EU a couple years ago (mostly thanks to FFII), trade negotiations are very secretive affairs and it is very hard to lobby there directly. The public needs to be aware of the issue, otherwise the politicians will not be aware of its importance to their voters. Software patents are a threat to free software as it circumvents the power of GPL and other copyright licenses if enough money is thrown at the lawyers. If a software patent is generic enough, it can easily stop development of a whole class of free software applications on a whim of the patent holder. And there are plenty of granted software patents with a very broad scope (progress bar, anyone?). I am aware that to get Debian support for such an initiative, a GR is needed, but how about a personal word of support from the DPL or support from the SPI? It is in direct area of interest for SPI - software patents create an ever present threat of legal action against any and all software in Debian (in USA and Japan, at least) and, as the legal umbrella of Debian in the USA, SPI would be a prime target. What do others think about this?

As September is traditionally the "conference month" I'll be travelling all around Germany within the next weeks. So, inspired by Matthew, here's a short list of events I'll attend in September 2008. If anyone's up for a coffee, keysigning or something let me know!

• August 31st to September 4th 9th European Conference on Case-Based Reasoning, Trier, Germany
• September 5th to September 7th 3rd Congress on Solidary Economy Bremen, Bremen, Germany (Will probably arrive on Saturday)
• September 23rd to September 26th 31st edition of the Annual German Conference on Artificial Intelligence, Kaiserslautern, Germany (Will probably arrive on Monday)

So, the string freeze for Debian Installer was announced today. It will last until Spetember 20th 23:59 UTC. We start with 13 complete languages and 15 meeting the release criteria. 60 (59+English) languages are currently supported. How many will meet the release criteria in 22 days?

If you happen to be near Bremen, Germany around the 5.-7. September 2008 and have an interest in solidary economy, free software, renewable energies and the like you might want to stop by at the 3rd Congress on Solidary Economy (German website). I haven't been at the first two of these congresses but I was invited as a speaker for this one, so I'll be around at least on Saturday and probably also on Sunday. I'll mainly be on a panel on free and open source software which will take place on Saturday evening at 20:00. (Prime Time :)) But I've also let myself be talked into joining another panel at 17:00 which is somehow ubuntu-related (Communtu). I am not yet sure if I'll have much to contribute there, I am neither a ubuntu specialist nor particularly fond of it, but the organiser said he wouldn't mind and he'd welcome critical remarks just as much, so, we'll see. I am really looking forward to being a speaker on an event again! Ever since I started my PhD I've been much too busy to attend (leave alone prepare talks for) as many events as I'd have liked. I hope the situation will improve next year when things get rolling with my PhD. (Currently still in a "topic orientation/find a project/write proposals" state ...)

Ouch. Absolutely no takers on the Squeezed Books contest: http://www.squeezedbooks.com/book/contest http://www.squeezedbooks.com/book/leaders I wonder what didn't work out? I mean, a book isn't a huge prize, exactly, but I know I've participated in mini-contests such as "leave a comment on my blog saying why you should win this book". I actually got a copy of Nick Carr's "The Big Switch" that way. And as it turns out, all it would have taken to win a free book in the Squeezed Books contest is an edit of a few words (as long as it wasn't random gibberish), so the 'barrier to entry' was pretty low. Perhaps I wasn't able to publicize it enough? Maybe the 'right' people didn't find it? Maybe people didn't find it credible? Too much of a pain to log in? The instructions aren't clear? It's tough - I am and always will be a programmer at heart, and this marketing stuff is harder than it seems! However, barring any sudden blinding insights, I'm going to try again. This time, whoever contributes the most to new or existing business book summaries by September 30th gets two business books of their choice, since we didn't give one away last time.